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Biomedical subjects

M Miceli

Publications and source records attributed to M Miceli.

At least 37 records · Page 2Linked to original sources
PubMed1998

Denial and its reasoning.

This work is aimed at analysing the motivated reasoning underlying denial of some piece of information. Denial is first distinguished from both repression and biased interpretation; then an analysis is provided of the reasoning devices typical of denial. The rules on which reasoned denial is based are similar to those governing the individual's normal cognitive activity. Reasoned denial is here represented in the form of if-then implications, where the to-be-denied belief plays the role of a consequence drawn from a given premise. So, in order to deny such a consequence one may either deny its premise, or search an alternative consequence, or search an alternative premise, or deny the very relation of implication, and so on. Each type of reasoning is logically biased, while at the same time psychologically plausible and convincing. A typical feature shared by all the reasoning strategies considered is the identification of 'unproven' with 'false'.

Defense Mechanisms↗
PubMed1998

Adult myeloid leukaemia, geology, and domestic exposure to radon and gamma radiation: a case control study in central Italy.

OBJECTIVES: To investigate whether indoor randon or gamma radiation might play a part in myeloid leukaemia as suggested by studies based on crude geographical or geological data for exposure assessment. METHODS: For six months randon and gamma radiation was measured with solid state nuclear track detectors and thermoluminescent dosimeters in dwellings of 44 adult male cases of acute myeloid leukaemia and 211 controls (all subjects deceased). Conditional logistic regression ORs (ORs) and 95% confidence intervals (95% CIs) were estimated for quartiles of radon and gamma radiation and for municipality and dwelling characteristics. RESULTS: The risk of leukaemia was associated with an increasing urbanisation index (p value for trend = 0.008). An increased OR was found among those living in more modern houses (OR 3.0, 95% CI 1.4 to 6.6). Confirming the findings of a previous study in the same area, geological features bore a positive association with myeloid leukemia, even by adjusting for level of urbanisation. Contrary to expectations from the previous study, however, no association appeared between myeloid leukaemia and radon and gamma radiation; for the highest quartiles of exposure, ORs were 0.56 (95% CI 0.2 to 1.4) and 0.52 (95% CI 0.2 to 1.4), respectively. Considering only subjects who had lived > or = 20 years in the monitored home and adjusting for urbanisation, there was still no effect of exposure to radiation. CONCLUSIONS: In view of the limited numbers, the results do not in general refute a possible risk of myeloid leukaemia from exposure to indoor radon or gamma radiation, but decrease the credibility of such a relation in the area studied and also of other studies suggesting an effect without monitoring indoor radiation. Some other fairly strong determinants have appeared--that is, level of urbanisation and living in modern houses--that might need further consideration.

Acute Disease↗
PubMed1998

Glucose tolerance, insulin secretion and peripheral sensitivity in thalassaemia major.

Glyco-metabolic status was evaluated in 29 pubertal homozygous thalassaemics aged from 17 to 42 years and in 12 age-matched healthy subjects. Diagnosis of diabetes mellitus was assessed in 4 patients (13.8%), who became diabetic after the age of 18 years. With respect to controls non-diabetic patients exhibited significantly higher fasting plasma glucose levels and more sustained glycemic responses to oral glucose tolerance test, whereas their overall insulin output was significantly lower. Moreover non-diabetic thalassaemic patients showed a clear reduction of both beta-cell function and insulin resistance indices (HOMA model). In conclusion our data show a high prevalence of diabetes but do not support the existence of an insulin resistant status in thalassaemia major, at least in adulthood.

Adolescent↗
PubMed1996

NMDA receptors play an anti-aggregating role in human platelets.

Receptors for different monoamines, peptides and other neurohormones are present in the plasma membrane of platelets, and the sophisticated process of haemostasis is regulated by the interplay of their physiologic agonists (1). The recent report of a platelet binding site for phencyclidine (2) suggested a possible role of N-methyl-D-aspartate (NMDA) receptors in platelet function. Isotherms of [3H]-glutamate (GLU), [3H]-CGP-39653, [3H]-glycine (GLY) and [3H]-MK-801 carried out in platelet membranes yielded Bmax and Kd values for these ligands similar to those present in neurons, and NMDA only partially displaced [3H]-GLU. In neurons [3H]-MK-801 binding is potentiated by GLU and/or GLY and, being specific for the open NMDA receptor channel species, it has a functional meaning. In platelet membranes neither GLU and/or GLY increased [3H]-MK-801 binding; thus suggesting that NMDA receptors in platelets are different from those present in neurons. GLU or NMDA alone did not induce platelet aggregation. However, both amino acids were antagonistic on the aggregating activity of arachidonic acid (AA), NMDA being 3 orders of magnitude more active than GLU, and NMDA also antagonized adenosine diphosphate (ADP) and platelet aggregating factor (PAF) induced platelet aggregation. Finally, NMDA increased cAMP levels in intact platelets, and such an effect did not occur in a Ca(2+)-free medium; yet, cAMP increase was not antagonized by the calmodulin inhibitor trifluoperazine (TFP). It was concluded that platelet membranes carry an NMDA receptor, functionally distinct from the neuronal one, which seems to play an anti-aggregating role.

Cyclic AMP↗
PubMed1995

Plasma and platelet taurine are reduced in subjects with insulin-dependent diabetes mellitus: effects of taurine supplementation.

Plasma and platelet taurine concentrations were assayed in 39 patients with insulin-dependent diabetes mellitus (IDDM) and in 34 control subjects matched for age, sex, and both total and protein-derived daily energy intake. Platelet aggregation induced by arachidonic acid in vitro at baseline and after oral taurine supplementation (1.5 g/d) for 90 d was also studied. Plasma and platelet taurine concentrations (mean +/- SEM) were lower in diabetic patients (65.6 +/- 3.1 mumol/L, or 0.66 +/- 0.07 mol/g protein) than in control subjects (93.3 +/- 6.3 mumol/L, or 0.99 +/- 0.16 mol/g protein, P < 0.01). After oral supplementation, both plasma and platelet taurine concentrations increased significantly in the diabetic patients, reaching the mean values of healthy control subjects. The effective dose (mean +/- SEM) of arachidonic acid required for platelets to aggregate was significantly lower in diabetic patients than in control subjects (0.44 +/- 0.07 mmol compared with 0.77 +/- 0.02 mmol, P < 0.001, whereas after taurine supplementation it equaled the mean value for healthy control subjects (0.72 +/- 0.04 mmol). In in vitro experiments, taurine reduced platelet aggregation in diabetic patients in a dose-dependent manner, whereas 10 mmol taurine/L did not modify aggregation in healthy subjects.

Adult↗
PubMed1995

Glutathione, glutathione utilizing enzymes and thioltransferase in platelets of insulin-dependent diabetic patients: relation with platelet aggregation and with microangiopatic complications.

Reduced glutathione (GSH) and activity of GSH related enzymes play a key role in defence against oxygen free radicals, whose production is, as known, raised in patients affected by diabetes mellitus, and at the same time they may contribute to the process of platelet aggregation. The purpose of this study was to evaluate GSH levels and activity of glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-Red), glutathione transferase (GSH-Tr), glucose-6-phosphate-dehydrogenase (G6PDH), and thioltransferase (TT) in platelets of insulin-dependent diabetic patients in fair metabolic control (mean glycated haemoglobin: 6.5%), as related to presence of retinopathy, neuropathy or nephropathy and to platelet aggregation by arachidonic acid (AA) in vitro. Mean effective dose (ED50) of AA was on average significantly lower in the group of insulin-dependent diabetic patients (0.41 +/- 0.02 mM (SEM), n = 46) as compared with that of control subjects strictly matched for age, sex and weight (0.77 +/- 0.02, n = 51; P = 0.0001). Mean platelet GSH as well as the activity of GSH related enzymes expressed as geometric mean (95% confidence intervals) were similar in diabetic patients and in controls, except for GSSG-Red whose activity was significantly higher in diabetic subjects (28.5 (14.4-57.5) mU 10(-9) platelets vs. 20.3 (8.7-56) mU 10(-9) platelets; P = 0.01). In the diabetic group TT was reduced when compared with healthy controls (3.8 (0.9-12.2) mU 10(-9) platelets vs. 6 (1.6-26.1) mU 10(-9) platelets; P = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Incidence of silicosis among ceramic workers in central Italy.

The incidence of radiological silicosis was studied among 2480 male workers employed in the ceramics industry. The subjects entered the surveillance program during 1974-1987 and were followed through 1991 with annual chest radiographs. The cumulative risk of silicosis (1/1 or greater; p,q,r) reached 48% (95% confidence interval 41.5-54.9) after 30 years of employment. In a multivariate Cox's proportional hazards model, the effect of duration of exposure increased linearly up to the category of 25-29 years; an extremely high hazard risk of 14.6 was found among those with 30 years or more of exposure in comparison with those employed 10 years or less. Smoking habit also significantly contributed to the model, although its role in the biological process is unclear. In conclusion, exposure to silica dust has been associated with a high incidence of silicosis among ceramics workers. The risk estimates are consistent with the recent findings of silicosis incidence among South African gold miners.

Adolescent↗
PubMed1994

Mortality among urban policemen in Rome.

A total of 3,868 urban policemen in Rome were investigated through a historical cohort study with emphasis on mortality from cardiovascular disease and cancer. Overall mortality from cardiovascular disease, respiratory conditions, digestive and genitourinary diseases, and accidents was lower than expected. An excess risk of ischemic heart disease was observed among subjects aged less than 50 years [14 deaths, standardized mortality ratio (SMR = 1.63), 95% CI = 0.89-2.73], corresponding to workers with a short duration of employment and a short latency since first employment. Overall cancer mortality was as expected and no excess was found for lung cancer (82 deaths, SMR = 1.05). Increased mortality was observed from colon cancer (16 deaths, SMR = 1.47), melanoma (four deaths, SMR = 2.34), bladder cancer (13 deaths, SMR = 1.27), renal cancer (seven deaths, SMR = 1.39), and non-Hodgkin's lymphoma (six deaths, SMR = 1.51), although none of the excesses were statistically significant. Two deaths from male breast cancer (SMR = 14.36) and three from cancer of endocrine glands were found (SMR = 3.44). Nested case-control studies were conducted to evaluate cancer mortality risk by job category. Bladder cancer was significantly increased among car drivers (OR = 4.17); for kidney cancer, an increased odds ratio (OR = 2.27) was found among motorcyclists; non-Hodgkin's lymphoma clustered among motorcyclists (OR = 5.14). In summary, excess risk for specific cancer sites (colon, male breast, and endocrine glands) might be linked to occupational exposures; professional drivers seem to be at higher risk of bladder cancer, kidney cancer, and non-Hodgkin's lymphoma.

Adolescent↗
PubMed1994

Renal excretion of ascorbic acid in insulin dependent diabetes mellitus.

Serum ascorbic acid (AA) is reduced in diabetic patients. Aim of this study was 1) to verify whether such a decrease might be due to an altered urinary excretion of AA, and 2) whether this latter was modified in presence of early diabetic nephropathy with microalbuminuria (albumin excretion rate [AER] > 20 micrograms/min) in a group of 21 patients affected by insulin-dependent (type 1) diabetes mellitus (IDDM) as compared with 13 healthy controls matched for sex, age, dietary AA intake, and creatinine clearance per 1.73 m2 (CCl). Mean serum AA (+/- SD) was lower in diabetics (40.3 +/- 14 microM/l) than in controls (85.1 +/- 23.5 microM/l; p = 0.0001) and there was no difference between serum AA of patients with or without microalbuminuria. Urinary excretion of AA to creatinine x 100 (UAA/Cr) was higher in micro- (n = 6; 4.6 +/- 1.7) as compared to normoalbuminurics (n = 15; 1.6 +/- 0.9) or controls (1.5 +/- 1.2; p = 0.0001). For values exceeding renal threshold of tubular AA reabsorption (39 microM) the regression line of serum AA to UAA/Cr was significantly (p = 0.001) steeper in diabetics than in controls, suggesting an impaired tubular reabsorption of filtered AA in IDDM. The ratio of AA clearance to CCl was moreover related to AER (r = 0.48; p = 0.03) and to blood glucose (r = 0.51; p = 0.01), being unrelated to uric acid clearance, glycosuria and to urinary excretion of both alanine aminopeptidase and N-acetyl-beta-glucosaminidase.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗
PubMed1993

Cancer among farmers in central Italy.

This case-referent study evaluated cancer risks among farmers in central Italy. Cancer cases (N = 1674, 17 sites) were selected from all deceased men aged 35-80 years; a random sample of 480 decedents formed the reference series. Farmers had a decreased risk of lung and bladder cancer and melanoma and nonsignificant excess risks for stomach, rectal, kidney, and nonmelanoma skin cancer. Stomach and kidney cancer were significantly increased among the farmers with > 10 years' experience, and stomach, rectal, and pancreatic cancer were increased among licensed pesticide users with > 10 years' experience. Possible relationships emerged between specific crops and cancer: fruit and colon and bladder cancer, wheat and prostate cancer, olives and kidney cancer, and potato and kidney cancer. The results regarding stomach, pancreatic, lung, bladder, and prostate cancer and melanoma congrue with earlier results. The kidney cancer excess, the association of colon and bladder cancer with orchard farming, and the excess of rectal cancer among licensed farmers are new and unexpected findings.

Adult↗
PubMed1992

[Conventional radiology, digital radiology with photostimulable phosphor, laser digitalization of thoracic radiographic films at the bedside. A comparative study].

The bedside chest images obtained with conventional radiology and with "on line" and "off line" digital modalities were compared to evaluate the respective capabilities in visualizing chest anatomical structures. Seventy patients were submitted to bedside chest examinations with a portable unit; both a conventional film and a digital system (PCR Graphics 1, Philips) with photostimulable phosphor imaging plate were fitted in the radiographic cassette. The former was digitized using an "off line" laser beam unit (FD 2000, Dupont); the latter was subsequently postprocessed by modifying contrast, optical density and spatial frequencies. Thus, 4 different viewing modalities were obtained for each examination: a) conventional radiography; b) standard digital radiography; c) postprocessed digital radiography; d) digitized conventional radiography. Detectability rates of chest anatomical structures were analyzed by 4 independent radiologists on the different images and expressed by a score 1-4. The values were always higher with digital modalities than with the conventional one and the differences were statistically significant (Student's t-test modified by Bonferroni). In particular, the greatest difference was found between c) and a) in retrocardiac lung parenchyma and in skeletal structures, in favour of c). Concerning the comparative adequacy of the various digital modalities, higher detectability rates of chest anatomical structures were obtained with c), but also with b), than with d).

Humans↗
PubMed1992

[Digital radiology with photostimulable image plates and conventional radiology in the study of the interstitial pathology of the lung].

To evaluate the diagnostic possibilities of Digital Radiography (DR) and of Conventional Radiography (CR) in the diagnosis of fine chest lesions, 100 patients with AIDS were examined with both techniques. The gold standards were 67Ga scintigraphy and bronchial washing in 100 patients and Computed Tomography (CT) in 50 patients. The data obtained from DR and CR examinations were separately evaluated by 4 readers and subsequently analyzed by ROC curves with Standard Error calculation and by comparing the areas below the characteristic curves with Student's paired t-test (p less than or equal to 0.05). Statistical analysis showed DR and CR to be of equivalent diagnostic value in the study of interstitial lung diseases.

Humans↗
PubMed1991

Persistence of HIV-1 silent infection in seronegative subjects at high risk.

Twenty regular sexual partners of HIV-1 infected subjects, without detectable human immunodeficiency virus (HIV-1) antibody and positive for HIV-1 genome by in situ hybridization (ISH), were selected and studied longitudinally for 6-36 months to estimate the duration of silent infection. During the follow-up period, 10 showed atypical Western Blot (WB) patterns. Two seronegative partners seroconverted. Rapid progress to AIDS was observed in 7 seropositive subjects.

Adult↗
PubMed1991

5-Acyl-6-aryl-4-nitro-3(2H)pyridazinones and related 4-amino compounds: synthesis and pharmacological evaluation.

Several 4-nitro- and 4-amino-5-acyl-6-aryl-3(2H)pyridazinones were prepared and their in vitro and ex vivo antiaggregatory properties were evaluated. 4-Nitro derivatives 3 generally showed good activity in vitro towards arachidonic acid (AA)-induced human blood platelet aggregation. The 4-amino compound 4a, which has weak in vitro activity, exhibited antiplatelet activity, particularly on adenosine dephosphate (ADP)-induced aggregation ex vivo in rabbit. Moreover, the same compound was shown to be active in platelet-activating factors (PAF)-induced rat paw hyperalgesia and to be endowed with low acute oral toxicity. The 4-amino derivatives 4a-m and the other pyridazinones 5-9 administered orally to rats were also found to be more potent antiinflammatory agents than acetyl salicylic acid (ASA). Compounds 3a and 4a, tested in vitro on lipopolysaccharide (LPS)-stimulated rat peritoneal macrophages, were seen to be active in the inhibition of prostaglandin E2 (PGE2) production and interleukin-1 activity. Structure-activity relationship studies in the series of antiaggregating pyridazinones 3 have shown the primary importance of the nitro and acetyl substituents at positions 4 and 5, respectively. Hydrophobic substituents at position 2 were also required for better activity.

Amrinone↗